A variety of radio devices are available, from those formed of discrete analog components as in conventional radios such as traditional broadcast radios, 2-way radios such as walkie-talkies, to more advanced radios. As technology advances, radio devices are formed with fewer components and can even be integrated into single chip devices. Such radios can be used for broadcast reception. In addition, radios can be implemented using transceivers that provide for both transmit and receive functionality. Such transceivers are often incorporated within a wireless telephone to provide for wireless voice and data communications.
In general, wireless signals are communicated as radio frequency (RF) signals and when received in a radio, are processed and downconverted to a lower frequency at which various demodulation, decoding and so forth is performed. In a transmit direction, oftentimes digital signals are processed to provide a given modulation. These signals are then converted to an RF signal for transmission from the radio.
To effect frequency conversion, both in upconversion and downconversion directions, one or more mixers can be used. In general, a mixer receives a signal at a first frequency and converts it to a signal of a different frequency, either higher or lower than the received signal. This control of the mixer generally occurs based on a mixing signal, which can be received from a local oscillator.